https://www.pcgamer.com/fortnite-rubber-duckies-locations/

Video: how to find all 19 of the rubber duckies locations in this Fortnite weekly challenge. 

Week three of Fortnite Season 4 Battle Pass has arrived, and among the weekly challenges, you'll be tasked to 'search rubber duckies' in your journey to secure those new cosmetics. You'll need to find 10 of them. This video from our friends at GR+ reveals the location of all 19 rubber duckies to help you complete the challenge—as you'll see, they're buried away in some pretty random places, but we'll help you complete the challenge nice and efficiently.